Question

An exposure was made using 8 mAs and 60 kV. If the kilovoltage was changed to 70 to obtain longer-scale contrast, what new milliampere-seconds value is required to maintain density?

4

Answer 1

To adjust mAs when changing the kV from 60 to 70 in X-ray production for maintaining image density, awareness of the specific adjustment factor or rule is required, which is not provided by the student.

Step-by-step explanation:

The student's question pertains to the principles of X-ray production and radiographic exposure. When the kilovoltage (kV) is increased from 60 kV to 70 kV, to maintain image density with the resultant longer-scale contrast, an adjustment in milliampere-seconds (mAs) needs to be done according to the exposure factors' reciprocity. The mAs and kV relationship generally suggests that an increase in kV by 15% will double the exposure, thus allowing to halve the mAs value to maintain density. However, since the student hasn't provided a specific rule or factor for adjustment, an exact new mAs value cannot be calculated without additional information.